Source · Paper

Counterexamples to Schiffer’s Conjecture

PreprintPublication date Aug 5, 2026
Open paper ↗

Reading source record 2026-08-05. View default cited record →

Overview

Constructs infinitely many symmetry orders with smooth star-shaped non-disk counterexamples through a uniform bifurcation argument.

Source publication and attributed assessments are distinct from independent OpenMath review.

Passages

The exact passages cited in OpenMath. Each passage identifies how its wording was recorded.

Passage 1 · OpenMath paraphrasePermalink

Theorem 1.1, Corollary 1.2 and AI/Lean acknowledgement

Constructs infinitely many symmetry orders with smooth star-shaped non-disk counterexamples through a uniform bifurcation argument.

Passage details

Passage ID: schiffer-pompeiu:entry:bifurcation:v1

Source item: bifurcation

Source record: schiffer-pompeiu:source:bifurcation:v1

Used in

Explicit citations in versioned problem publications. A citation records a use; it does not confer proof or independent verification.

Schiffer and Pompeiu conjectures →

Problem publication v7

Infinitely many smooth symmetry orders →

Source assessment

Proved

Infinite family of smooth counterexamples proved in the cited paper

Infinitely many integers N ≥ 2; bounded simply connected star-shaped C∞ domains with N-fold symmetry.

Source date Aug 5, 2026 · Observed Oct 13, 2026

Problem context · 4 citations

History

Pompeiu asks whether domain averages determine a function

Further reading

Read the mathematical argument; inspect its Claim for assessment and scope.

Credits

Recorded authorship

Gonzalo Cao-Labora · Jaume de Dios Pont

Gonzalo Cao-Labora, Jaume de Dios Pont

AI involvement reported by the source

The authors credit GPT-5.5/5.6 and Claude Opus 4.8/Fable 5 for exploration, checks and exposition; GPT-5.6 assisted the early-draft Lean verification. The authors retain responsibility.

Versions

OpenMath source records preserve exact citations. Observation dates order these records; they do not establish the latest upstream paper or proof.

  1. 2026-08-05 · selectedObserved Oct 13, 2026 · used in current publications

    Counterexamples to Schiffer’s Conjecture

Record details
Source ID
schiffer-pompeiu-bifurcation
Record ID
schiffer-pompeiu:source:bifurcation:v1
Recorded title
Counterexamples to Schiffer’s Conjecture
Revision
2026-08-05
Observed
Oct 13, 2026
Source updated
Not recorded
Content SHA-256
857b2f4975bfc4b2ccc113020bf6e9fc9e1ef36c4caa09c09ff73e08f7840026
Update method
Compare the exact source and publish a new immutable curation revision.
Identifier policy
Stable source identity with exact versioned passages.
Check interval
90 days
Rights
metadata-link
License
Original source license and document rights apply.

OpenMath supplies its own mathematical paraphrases and links; proof text is not republished.

Source terms ↗